The present invention relates to a position recognizing device and a position recognizing method for recognizing a position of a light emitting unit.
For optical three-dimensional pointing devices and motion capture systems for capturing motion of a human body and thereby generating data for creating animation, a method is proposed which makes a plurality of light emitting units, for example LEDs (Light Emitting Diodes) sequentially emit light and detects the light by means of a CCD (Charge Coupled Device), a CMOS (Complementary Metal Oxide Semiconductor) image sensor or the like, or a PSD (Position Sensitive Device). By integrating information on two-dimensional positions of a light source on image sensors or PSDs on principles of stereoscopic vision, it is possible to determine a three-dimensional position of the light emitting source in a real space.
In order to detect positions of a plurality of LEDs on an image sensor or on a PSD, the plurality of LEDs are made to emit light sequentially, and at a certain moment, only light from one LED is received on a light receiving plane of the image sensor. Therefore, synchronization between the LEDs and the image pickup device is required, and a signal transmission line (wire or radio) is required between the plurality of LEDs and the image pickup device, thus presenting a problem of a complex system.
The present applicant has proposed a system in which a transmitter including a circuit for generating an ID associated with an object and an LED blinking according to the ID is attached to the object, the blinking light is photographed by means of a CMOS image pickup device or the like having a relatively high frame rate, a received signal is decoded for each pixel of the image pickup device, the ID is obtained, and thereby the position of the LED on a light receiving plane of the image pickup device is determined. This system has a problem of a large scale of the image sensor and signal processing circuit.